原子层沉积低温生长α-MoO3薄膜

Low Temperature Growth of Polycrystalline Molybdenum Oxide Thin Films by Atomic Layer Deposition

摘要:

以六羰基钼和氧气为前驱体,通过等离子增强原子层沉积技术(PE-ALD)在硅基片上实现了α-MoO₃薄膜的低温制备。利用X射线衍射仪、扫描电子显微镜、原子力显微镜、X射线光电子能谱仪等手段对薄膜的晶体结构、表面形貌及薄膜成分进行表征和分析。研究发现衬底温度和氧源脉冲时间对MoO₃薄膜的晶体结构和表面形貌变化起关键作用。当衬底温度为170℃及以上时所制备的薄膜为α-MoO₃；适当延长ALD单循环中的氧源脉冲时间有利于低温沉积沿(0k0)高度择优取向的MoO₃薄膜。根据对不同厚度MoO₃薄膜表面的原子力显微图片分析,MoO₃薄膜为岛状生长模式。

Abstract:

Polycrystalline MoO₃ thin films were fabricated on silicon substrates at low temperature by plasma-enhanced atomic layer deposition (PE-ALD) using molybdenum hexacarbonyl and oxygen as precursors. Crystal structure, surface morphology, elemental composition of the deposited MoO₃ films were characterized by XRD, SEM, AFM and XPS. Results show that the crystal structure and surface morphology of the fabricated MoO₃ thin films are highly dependent on the substrate temperature and the pulse time of the oxygen plasma. When the substrate temperature is 170℃ and above, the as-grown film is α-MoO₃. Highly (0k0) prefer-orientated MoO₃ thin films can be obtained at 170℃ by properly prolonging the pulse time of oxygen plasma to 60s. The films are followed by the island growth mode based on the AFM analysis.